1. Field of the Invention
The present invention relates to a laser centering mechanism of a drilling machine, more particularly one, which is secured to a drill chunk of a drilling machine, and which consists of two laser modules capable of emitting laser lights forming two intersecting lines on a workpiece for helping a drill of the drilling machine to be centered on a predetermined point of the workpiece, on which a hole is to be drilled; only the intersection of the perpendicularly intersecting lines can be seen when the drill is rotating due to persistence of vision.
2. Brief Description of the Prior Art
Referring to FIG. 1, a conventional drilling machine has a support base 11, a support rod 12 joined to the base 11, and a table 13 supported on the support rod 12 for a workpiece 10 to be positioned on; fixing jaws 19 are disposed on the table 12 for fixing the workpiece 10 in position; a power source 14 is disposed above the table 12, and has a support tube 17, and a transmission shaft (not shown), which sticks downwards within the support tube 17, and to which a drill chunk 15, and a drill 16 are connected. A control member 18 is joined to the support tube 17 so that the support tube 17 can be moved down for the drill 16 to drill holes on the workpiece 10 by means of operating the control member 18.
In order for the drill 16 to drill a hole on a workpiece at a predetermined position, the workpiece is usually first formed with a shallow mark at the predetermined point to be drilled by means of a centering punch before it is fixed on the table 13 with the jaws 19. A shallow hole can be first drilled at the predetermined point of a workpiece with a centering drill instead before the drill 16 is used to drill a hole on the workpiece.
Both of the above ways is not very convenient to use because the operator has to watch carefully to establish whether the drill is centered on the shallow mark while he is operating the control member 18 to move the drill onto the workpiece, causing labor and time to increase in manufacturing. Consequently, the cost of production is relatively high.